His mother, Marie Helena Susanna von Tucher (1791–1855) came from a long-established Nuremberg family of nobility.
In 1847, he published two volumes of the History of Urban Constitution of Italy since the Time of the Roman Empire until the End of the 12th Century.
From 1862 to 1899, 27 volumes of the edition “Die Chroniken der deutschen Städte” were published by Karl Hegel for the Historical Commission of the Bavarian Academy of Sciences and Humanities in Munich.
Hegel edited six chronicles volumes (Nuremberg, Strasbourg and Mainz) in many parts on his own.
Designated historians, specialists in German studies and jurists such as Karl Lamprecht, Georg von Below, Matthias Lexer or Ferdinand Frensdorff were his employees.
This representation was a standard work with good international reviews and reputation (for example: Friedrich Keutgen: Städte und Gilden der Germanischen Völker im Mittelalter.
In 1901, the dean of the philosophic faculty of the university of Erlangen Richard Fester[6] honored him in his funeral eulogy about Karl Hegel as "Städtehegel".
[7] His scientific estate is located largely in the Manuscript Department of the University Library of Erlangen-Nuremberg.
Thus, the current department keeps the founder of the Historical Institute of the Friedrich-Alexander University in memory.
The Department of History at the University of Erlangen-Nuremberg is researching Karl Hegel's life in several studies Helmut Neuhaus.
In 2012, Marion Kreis published her book on Karl Hegel's historiographical significance[9] and ends with this "meritorious study" this desideratum[10] A list of publications can be found in Marion Kreis, Karl Hegel.